Monitoring Mekong River level change by satellite altimetry

Mekong River, a major freshwater resource for the mainland Southeast Asia, has a length more than 4000 km with distinct seasonal changes in width and discharge. To react to the possible water resource crisis in this area, some of adjacent countries started to build dams along the Mekong in the last decade for retaining water within the border. The construction of dams has been benefit to some of the collaborated countries in water supply and hydropower generation. However, block of river has induced a conflict within this region due to the altered upstream-downstream connectivity. In this study, we utilized two altimetry satellites, Envisat and Jason-2, to observe the water level variation in the last 12 years (2002-2014) at both upstream and downstream of two lately built Jinghong Dam and Nuozhadu Dam, located in Yunnan Province, China. By using the technique of radar altimetry waveform retracking, the water level variation within steep terrain is clearly detected in terms of both man-made impoundment and seasonal changes. The observation of water level across the whole basin is expected to be a good reference for local authorities to revise modulation of water dynamics and for a timely update of infrastructure planning.